Warp control device



E. PFARRWALLER WARP CONTROL DEVICE Jan. 12, 1960 2,920,659

Filed April 8, 1957 2 Sheets-Sheet 1 20 1 I 19v i/ 18 v J A??? 51 54 55 53 I INVENTOR. ERW/N R'ARRWALLER.

ATTO RNEK Jan. 12, 1960 E. PFARRWALLER 2,920,559

WARP CONTROL DEVICE I Filed April 8, 1957 2 Sheets-Sheet 2 64- 30 67 3] 66 65 Fig. 2

-40 Fig. 3 41. 47

INVENTOR. E/PW/N PFARRWA LLE/F.

ATTORNE).

United States Patent WARP CONTROL DEVICE Erwin Pfarrwaller, Winterthur, Switzerland, assignor to Sulzer Freres, S.A., Winterthur, Switzerland, a corporation of Switzerland Application April 8, 1957, Serial No. 651,266

Claims. priority, application Switzerland April 13, 1956 6 Claims. (Cl. 139-110) The present invention relates to a device for controlling the warp in a weaving machine and more particularly to means for actuating a clutch interposed in the drive of the warp beam for periodically releasing a predetermined length of warp from the warp beam and for changing the durations of the periodic engagements of the clutch and thereby the angle of the periodic rotation of the warp beam according to the tension of the warp.

The present application is a continuation-in-part application of my application Serial No. 406,116, filed January 26, 1954, now US. Patent No. 2,819,734.

The device according to the invention includes a movable element whose movements depend on the changes of the length of the warp threads between the warp beam and the fabric, the movements of the element being transmitted to actuating means for a clutch which is interposed in the drive of a warp beam and which actuating means periodically engage the clutch in timed relation to the weaving operation.

The novel features which are considered characteristic of the invention are set forth with particularity in the appended claims. The invention itself, however, and additional objects and advantages thereof will best be understood from the following description of embodiments thereof when read in connection with the accompanying drawing in which:

Fig. 1 is a part sectional side elevation of a device according to the invention;

Fig. 2 is a part sectional top view of the clutch portion of the device shown in Fig. 1;

Fig. 3 is a diagrammatic side view of a modified detail of the device shown in Figs. 1 and 2;

Fig. 4 is an end view from the left side of Fig. 2.

Like parts are designated by like numerals in different figures of the drawing.

Referring more particularly to Fig. 1 of the drawing, numeral designates Warp threads which are pulled from a warp beam, not shown, and which are laid over a warp tensioning beam 11. Each end of the latter is provided with a pin 12 which rests in a bearing 13 provided at the end of a tensioning lever 14. The levers 14 are supported by a shaft 15 which is carried by a bracket 17 mounted to the frame 9 of the weaving machine. Each lever 14 has an arm 18 whose periphery is provided with a plurality of notches for selectively placing a bolt member 20 which is pulled by means of a spring 21 towards a stationary point 8 on the frame 9. The warp 10 moves from the tensioning beam 11 to the right in the conventional manner through warp thread feelers, heddles, and a reed, to the right end of the machine where the finished fabric is wound on a fabric beam.

A special device is provided for controlling the drive of the warp beam. This drive includes a clutch having clutch discs 30 and 31, the clutch being interposed between a shaft 32 which is connected with the main drive ,pfthe loom, not shown, and a worm gear including a "ice worm 33 and a worm wheel 34. The latter drives the warp beam through additional gears, not shown.

An arm 36 extends from a pin which is axially inserted in the shaft 15 which supports the tensioning levers 14, the pin 35 being provided with a collar 37 which is held to the shaft 15 by means of a ring 38 secured by bolts 39 so that the arm 36 is made fast on the shaft 15 and its angular position relatively to the shaft 15 can be changed, if desired, by loosening the bolts 39.

A link member 40 connects the arm or lever 36 with the left arm of a lever 41. At the end of the right arm of the lever 41 a guide groove 42 is provided which is curved around the fulcrum 47 of the lever 41. A slide element 43 is placed in the groove 42, the element 43 oscillating on a pin 44 mounted on a casing 45 which is connected with the frame of the Weaving machine. The fulcrum of the lever 41 is placed between a pin 46, which connects the link' 40 with the left arm of the lever 41, and the slot 42. A pin 47 forming the fulcrum of the lever 41 is mounted on a lever 48, extending from one end of a pin 49 which is rotatably carried in the casing 45. An arm 51 is secured to the other end of the pin 49 by means of a bolt 52 partly extending through the pin 49 (Figs. 2 and 4). The hub portion of the arm 51 may be radially split so that it is pressed against the pin 49 when the bolt 52 is tightened. The arm 51 extends downward, as seen in Fig. 1, a cam follower roller 54 being rotatably connected with the lower end of the arm 51 by means of a pin 53.

The roller 54 engages an annular cam 55 provided on the clutch disc 3! coaxially thereof and projecting in axial direction. The disc 30 is connected with the shaft 32 by means of a conical pin 56 (Fig. l). The shaft 32 is inserted in a hollow shaft 57 to which the worm 33 is connected by a pin 58. The worm 33 drives the worm wheel 34 for rotating the warp beam, not shown. The clutch disc 31 is mounted on the hollow shaft 57 and is axially movable thereon, splines 59 being provided on the outside of the shaft 57 and on the inside of the hub of the disc 31 for preventing rotation of the clutch disc 31 relatively to the shaft 57. The clutch disc 31 is pressed to the left by means of a compression spring 61 whose right end presses against a plate 62 which rests on a bearing 63 mounted in the casing 45. The clutch disc 31 is provided with a flange 64 which engages a brake lining 65 mounted on a flange 66 of the casing 45 (Fig. 2) when the disc 31 is in the extreme left position. One or both clutch discs 30 and 31 are provided with a friction lining 67.

The clutch disc 31 is connected with the drive of the warp beam. The clutch disc 30 is driven by the main drive of the weaving machine. It is periodically axially moved depending on the configuration of the cam 55 which is engaged by the roller 54.

The periodic axial displacement of the coupling part 39 is also responsive to the position of an element which is responsive to the change of the length of the wam threads unwound from the warp beam and extending between the latter and the fabric. In the embodiment shown in Figs. 1 and 2, this element is the warp tensioning beam 11.

The device operates asfollows:

When the shaft 32 is rotated the surface of the cam 55 moves along the roller 54, effecting the described periodic reciprocating movement of the clutch part 30. If this movement is directed to the right in Fig. l and exceeds the distance a the clutch part 30 engages the clutch part 31 and, upon continued movement to the right, the brake flange 64 is disengaged from the brake lining 65. This movement to the right is effected against the action of the spring 61. The clutch is now engaged and rotated by the shaft 32, so that also the worm gear 33, 34 is actuated and a certain amount of warp 10 is unwound from the warp beam until the clutch disc 30 is permitted to move to the left by the cam 55. At the moment of disengagement of the disc 30 from the disc 31 the brake 64, 65, 66 is engaged and rotation of the shaft 57 and of the worm gear 33, 34, and parts connected therewith is interrupted.

While the clutch was engaged and the brake disengaged, the worm 33 rotated through an angle corresponding to the rotation of the clutch disc 3% between the moment of engagement with and the moment of disengagement from the clutch disc 31. This angle of rotation is usually substantially smaller than 360, if the shaft 32 rotates at the same speed as the main drive shaft of the weaving machine. The angle may temporarily be as much as 360. The ascending and descending portion of the surface of the cam 55 may extend through the same angle. The cam, however, may also be so constructed that the ascending portion is considerably greater than the descending portion; for example, the ascending portion may extend through 270 and the descending portion through 90, so that there is a smooth engagement of the clutch and a quick disengagement of the clutch and quick braking of the warp beam. The initial tension of the spring 61 is preferably so that the clutch disc 31 is rotated without slippage by the disc 30, also at the greatest possible load on the worm gear 33, 34.

The warp beam is somewhat rotated at every revolution of the shaft 32 and a certain length of warp is released by the warp beam. The tension of the warp It is maintained by the spring '21 which acts on the tensioning beam 11 through the lever 14, 18. As long as the length of warp unwound from the warp beam corresponds to the length of warp required for the weaving operation the position of the tensioning beam '11 and the tension of the warp 16 do not change.

As long as the distance a between the disengaged clutch discs 30 and 31 remains the same, the angle of rotation of the warp beam will be the same at each revolution of the shaft 32. This angle of rotation will release considerably more warp when the warp beam is wound to capacity than when there are only a few windings left on the warp beam. Disregarding other influences this alone will cause a gradual reduction of the length of warp released by the warp beam and a lowering of the tensioning beam 11, causing a counterclockwise rotation of the arm 36 and pulling up of the link 46. Adjustment screws 68 and 69 may be provided on the link 40 which are adapted to abut against a head 70 of the arm 36. If there is no clearance between the screws 68, 69 and the head 70, the lever 41 is immediately swung on the fulcrum 47. This causes a clockwise movement of the slot 42 and a displacement of the fulcrum 47 to the left because the distance b of the lower end of the center line of the slot 42 from the fulcrum 47 is smaller than the distance b of the upper end of the center line 0 from the fulcrum 47. Movement of the fulcrum 47 to the left in Fig. 1 causes counterclockwise rotation of the pin 49 and of the arm 51 so that the roller 54 is moved to the right, pushing the clutch disc 35) in the same direction. The clutch disc 30, therefore, engages the disc 31 sooner and the angle of rotation between engagement and disengagement of the clutch becomes greater. Therefore, the worm 33 rotates also through a greater angle, increasing the length of the warp unwound from the warp beam. The tensioning lever will, therefore, be raised if the previously unwound length of warp was too short and is now sufficient, because it corresponds to the length of the woven fabric. The tensioning beam 11 will now remain in its new position and the new spacing a between the clutch discs will also remain unchanged. The arrangement of the tension spring 21 and the position of the bolt '20 on the lever 16 as well as the position of the latter relatively to the shaft may be so chosen that the warp tension remains substantially constant in spite of a minor movement of the tension-beam 11.

If the warp tension is temporarily considerably changed when a weft thread is beaten up, the tensioning beam 11 is also lowered to a certain extent.

in order to avoid actuation of the warp control mechanism in response to these temporary variations of the warp tension a clearance d is provided between the adjusting screws 68 and 69 and the head 70 of the lever 36. If the tensioning beam 11 is lowered or raised more than provided for by the clearance d either the screw 63 or the screw 69 effects a displacement of the link 40 and an oscillation of the lever 41. Thereupon the eccentric slot 42 causes an angular movement of the arms 48 and 51 and a displacement of the cam follower roller 54 and of the clutch disc 30.

During the angular movement of the warp beam 2. force is transmitted through the spring 61 and the disc 31 to the clutch disc 30. This force does not affect the motion transmitting mechanism between the clutch disc 30 and the lever 14 which is responsive to the warp tension, because the slot 42 is so shaped that the friction of the slide member 43 is so great that the lever 41 is not oscillated.

Fig. 3 is a diagrammatic illustration of a modified mechanism for periodically displacing the clutch disc 30 and for supplementally displacing the disc in response to the tension of the warp. The disc 30 is provided with an annular axial protuberance 72 of uniform elevation. Periodic reciprocating movement of the clutch disc is produced by a roller 73 which has a frusto-conical configuration and whose rotation axis is eccentrically positioned in the roller 73. Movement of the tensioning beam 11 effects displacement of a slide 74 which rotatably supports the roller 73. Due to the conical shape of the member 73 the amplitude of the reciprocating movement of the clutch disc 30 and the duration of the periodic engagement of the clutch are changed upon axial movement of the member 73. The slide 74 is moved by means of a lever 51 which swings on a pin 49. The lever 51 has an arm whose free end is pivoted to and forms the fulcrum 47 of the two-arm lever 41, shown in Fig. l. The lever 41 is actuated by a link 40 in the same manner as in the device shown in Fig. 1.

The clutch disc 31 is provided with a spur gear 75. A pinion '76 is mounted on a shaft 78 provided with a hand wheel 77 and can be brought to engage the spur gear 75 by axial movement to the right of the pinion 76. The hand wheel 77 is preferably removably connected with the shaft 78 so that the same hand wheel can be used for several weaving machines. Upon rotation of the hand wheel 77 and movement of the pinion 76 to the right the disc 31 can be rotated and the warp beam can be made to wind or unwind a desired length of Warp.

A main advantage of the device according to the invention is that it has very small moving masses and can, therefore, effect a very sensitive control of the Warp.

I claim:

1. A device for controlling the warpin a weaving machine, comprising a frame, a warp beam rotatably supported by said frame, drive means for said warp beam, a clutch interposed in said drive means and having two mating discs, an element supporting the warp and being movably connected with said frame to move in accordance with the tension of the warp, one of said clutch discs benig axially movable for moving into and out of engagement with the other clutch disc, said movable clutch disc being provided with an annular cam coaxially of said clutch, a cam follower roller engaging said cam, support means for said roller, said support means being movably supported by said frame to move said roller in a direction substantially parallel to the rotation axis of said clutch, and a mechanism interconnecting said element and said support means for transmitting the motion of said element to said support means, said mechanism including a lever fulcrumed to said support means and adapted to swing according to the movement of said element, said lever having an arm provided with a guide slot arcuated around the fulcrum of said lever and having an end which is more distant from said fulcrum than the other end of said slot, and a slide member extending from said frame into said slot for displacing the fulcrum of said lever upon oscillation of the latter and moving said support means to move said camfollower roller in said direction, the curvature of said slot being so that movement is transmitted from said element to said support means and transmission of movement is prevented from said support means to said element.

2. A device for controlling the warp in a weaving machine, comprising a warp beam from which the warp is unwound, drive means for said warp beam, a clutch interposed in said drive means, said clutch having a driving part and a driven part, actuating means associated with said driving part for reciprocably moving the driving part towards and from'said driven part for periodically engaging said clutch, control means responsive to the tension of the warp and being connected with said actuating means for controlling operation of said actuating means and effecting the periodic engagements of said clutch according to the tension of the warp.

3. A device as defined in claim 2, in which said control means include means for shifting the axial position of the reciprocating clutch part in dependence on the tension of the warp.

4. A device as defined in claim 2, in which said control means include means for controlling the extent of the axial movement of the reciprocably moving clutch part in dependence on the tension of the warp.

5. A device for controlling the warp in a weaving machine, comprising a warp beam from which the warp is. unwound, drive means for said warp beam, a clutch interposed in said drive means, said clutch having two mating parts, actuating means associated with one of said mating parts for periodically axially moving the part with which it is associated against the other of said mating parts for periodically engaging said clutch, control means responsive to the tension of the warp and being connected with said actuating means for controlling operation of said actuating means and eifecting the periodic engagements of said clutch according to the tension of the warp, said actuating means including a cam rigidly connected with one of said mating parts, and a cam follower engaging said cam and being movably connected with a stationary part of the weaving machine to move in a direction substantially parallel to the rotation axis of said clutch, said control means being connected with said cam follower to move said cam follower in dependence on the tension of the warp.

6. A device for controlling the warp in a weaving machine, comprising a warp beam from which the warp is unwound, drive means for said warp beam, a clutch interposed in said drive means, said clutch having two mating parts, actuating means associated with one of said mating parts for periodically axially moving the part with which it is associated against the other of said mating parts for periodically engaging said clutch, control means responsive to the tension of the warp and being connected with said actuating means for controlling operation of said actuating means and effecting the periodic engagements of said clutch according to the tension of the warp, said control means including a movable element which is moved by the warp according to the tension of the warp, a mechanism operatively connecting said element with said actuating means, and a self-locking means interposed in said mechanism, said self-locking means including means transmitting motion from said element to said actuating means and preventing transmission of motion in the opposite direction.

References Cited in the file of this patent UNITED STATES PATENTS 

